This week’s presidential debate could mark the first opportunity for President Obama and Republican presidential nominee Mitt Romney to face off on marriage in a race in which LGBT issues have figured less prominently than previous elections.

The debate — the first in a series of three for the presidential candidates — is set to take place on Wednesday at the University of Denver. The topic for the 90-minute debate is domestic policy, and LGBT issues and marriage equality would fall under that umbrella.

The moderator of the debate is Jim Lehrer, the executive editor and former news anchor for PBS NewsHour. It’s unclear if he’ll ask a question on LGBT rights or marriage at the debate. But a question on LGBT rights could create an opportunity for Obama, who endorsed same-sex marriage in May, to attack Romney for not only opposing marriage rights for gay couples, but supporting a U.S. constitutional amendment banning same-sex marriage.

Evan Wolfson, president of Freedom to Marry, said if a marriage question was posed to the candidates during the debate, he’d like to hear Obama “repeat the same heartfelt personal explanation” that he offered in May when he announced he completed his evolution in support of marriage equality.

“And I’d like him to point out that just as it was wrong to deny couples of different races — like his parents — the freedom to marry, so under our Constitution, it is wrong to exclude couples of the same sex from the commitment of marriage and the freedom to marry under the law,” Wolfson said.

Even though marriage will be on the ballot in four states and lawsuits are pending before the Supreme Court that would overturn the Defense of Marriage Act and California’s Proposition 8, both candidates have remained largely silent on marriage and other social issues and have focused more on the economy and national security.

Crosby Burns, a research associate on LGBT issues at the Center for American Progress, said the two candidates’ differing views on marriage could “not be more stark.”

“You have Mitt Romney who supports a Federal Marriage Amendment that would define marriage as the union between one man and one woman,” Burns said. “And Barack Obama, on the other hand, as you know has come out in May in favor of full marriage equality. If he’s asked a question at next week’s debate in Denver, I fully expect him to reiterate his unyielding support for marriage equality.”

But Dan Pinello, who’s gay and a political scientist at City University of New York, predicted that if the candidates are asked a marriage question during the debate, they would give “very abbreviated answers” because neither Obama nor Romney sees political gain by elevating the issue of marriage.

“If Jim Lehrer does say something about it, I think Mitt Romney will say this is an issue the states have to decide — nothing a president will have any authority over, but a state issue,” Pinello said. “I think Barack Obama, if he’s forced to address it, will say what he’s said before: it’s a personal issue … whatever he said a few months ago. But they’ll try to step around the issue as much as they can.”

Circumstances were much different in the recent past. Just two presidential elections ago, when Sen. John Kerry (D-Mass.) was running against then-President George W. Bush for the White House, the issue of marriage was a cornerstone of the Republican campaign at a time when 13 marriage amendments were on the ballot in states throughout the country.

In his 2004 State of the Union address, Bush said the country “must defend the sanctity of marriage” by passing a Federal Marriage Amendment to prevent “activist judges” from instituting same-sex marriage in their states. Asked about the issue on the campaign trail, Kerry would uncomfortably say he believes marriage is one man, one woman, but doesn’t think the U.S. Constitution should be involved.

Four years later, the issue of same-sex marriage figured less prominently in the contest between then-Democratic candidate Obama and Republican nominee John McCain. It came up during a forum hosted by Pastor Rick Warren of California’s Saddleback Church, when McCain said he thinks marriage should be left to the states, but would support a constitutional amendment banning same-sex marriage if his home state of Arizona were forced to recognize it.

Obama also said he believed marriage is between one man, one woman because “God’s in the mix” — a position he has since changed — as he declined to support a Federal Marriage Amendment.